public void AddEntry(DataShiftingEntry entry)
{
if (entry == null)
throw new ArgumentException("Null entry found", entry.ToString());
Entries.Add(entry); //add entry to list
}
/// <summary>
/// Re-arranges total and used elements in given dictionaries and returns the counter of minimum drives still containing data
/// </summary>
/// <param name="uDict"></param>
/// <param name="tDict"></param>
/// <param name="minimum"></param>
private void Pack(ref Dictionary<int, int> uDict, ref Dictionary<int, int> tDict, out int minimum)
{
minimum = 0; // counter of minimum drives still containing data
int i, j = 0; // loop counters
List<KeyValuePair<int, int>> tList = tDict.OrderByDescending(v => v.Value).ToList<KeyValuePair<int, int>>();
HashSet<int> keysUsed = new HashSet<int>();
try
{
for (i = 0; i < tList.Count; i++)
{
int i_key = tList[i].Key;
int used = uDict[i_key];
int total = tList[i].Value;
int free = total - used;
if (free > 0) // disk has some space free
{
keysUsed.Add(i_key); //store dictionary key currently processed
for (j = 0; j < uDict.Count; j++) //read through dictionary of used sizes to
{
int currentUsed = uDict.ElementAt(j).Value; //store sender's current used size
//arrange used data if current used size is not zero and not already utilized and/or compared against itself
if (currentUsed != 0 && uDict.ElementAt(j).Key != i_key && !keysUsed.Contains(uDict.ElementAt(j).Key))
{
if (currentUsed == free) //sender send all of its used data, no left free space for the receiver
{
uDict[i_key] += currentUsed; //add used index of the same key
uDict[uDict.ElementAt(j).Key] = 0; //set sending used size to zero
free = 0; //disk is full
entry = new DataShiftingEntry(uDict.ElementAt(j).Key, currentUsed, i_key); //create log entry
consolidationLog.AddEntry(entry); //add entry to log
break; //exit the loop
}
else if (currentUsed < free) //sender send all if its used data, receiver has still free space
{
uDict[i_key] += currentUsed; //add used index of the same key
uDict[uDict.ElementAt(j).Key] = 0; //set sending used size to zero
free -= currentUsed; //disk is not full
entry = new DataShiftingEntry(uDict.ElementAt(j).Key, currentUsed, i_key); //create log entry
consolidationLog.AddEntry(entry); //add entry to log
}
else if (currentUsed > free) //receiver becomes full, while sender still has free space
{
uDict[i_key] += free; //add used index of the same key
uDict[uDict.ElementAt(j).Key] -= free; //calculate sender's new used size
entry = new DataShiftingEntry(uDict.ElementAt(j).Key, free, i_key); //create log entry
consolidationLog.AddEntry(entry); //add entry to log
free = 0; //disk is full
break; //exit the loop
}
}
}
}
}
}
catch (IndexOutOfRangeException ie)
{
ArgumentException argex = new ArgumentException("Index is out of range", ie);
throw ie;
}
int[] _used = new int[uDict.Count];
foreach (KeyValuePair<int, int> pair in uDict)
{
_used[pair.Key] = pair.Value; //copy to array
}
// count minimum number of disk drives that still contain data
minimum = countMin(_used);
}